Pulverizing machine



Jan. 18 1927.

A. M. READ PULVERIZING MACHINE Filed March 31 1921 3 Sheets-Sheet 1 WITESSES A? 40. 77

A TTOR/VEY Jan. 18', 1927. 5 v A. M. READ PULVERIZING MACHINE FiledMarch 51. 1921 SSheets-She'et 2- WIT/YES? M f w H f 4') I Q M amw Jan.18, 1927. 1,614,899

A. M. READ PULVERIZING mourns Filed March 31, 1921 Sheets-Shoot 3 53;: IQ Q G ,a 00cc I I 0 Q E 38 I! no r I A\ i w 3) INVENTOR S WITNESSES m7%;

A TTOK/V'EY Patented Jan. 18, 1927.

UNITED STATES vPATENT OFFICE.

ALEXANDER M. BEA D, OF COLUMBUS, OHIO.

PULVERIZING MACHINE.

Application filed March 31, 1921. Serial No. 457,176.

"he present invention relates to certain new and useful improvements inpulverizing machines of the class in which each consists of a rotatablebarrel wherein the material to be pulverized may be tumbled about withfreely movable crushing bodies to be pulverized by contact therewith.

In my co-pending application, Serial No. 348,506, filed December 31st,1919, I have disclosed a pulverizing machine embodying some of thefeatures of this invention.

It is the especial object of this invention to provide improved deviceswhereby the finished product will be promptly removed from the interiorof the mill.

Another object is to provide an improved arrangement of parts wherebythe screens and linings may be conveniently renewed.

Another ob ect is to provide means to protect the screen supportingdevices from the erosive action of the material in the pulverizingchambers.

These and other objects will appear in the following specificationwherein is set forth the preferred embodiment of my invention, referencebeing had to the accompanying drawings of which Fig. 1 is a sectionalview taken along the central longitudinal vertical plane of the mill.

Fig. 2 is a fragmentary front elevation on an enlarged scale of one ofthe screens by which the interior of the mill is divided into a seriesof pulverizing chambers.

Fig. 3 is a section taken along the line III-III of Fig. 2.

Fig. 4 is a fragmentary rear elevation of the screen illustrated inFigs. 2 and 3, certain parts being removed to reveal other parts.

Fig. 5 is a fragmentary rear elevation of the final screen by whichmaterial is removed from the pulverizing chamber. 7

Fig. 6 is a section taken along the line VI-VI of Fig. 5 to which hasbeen added the parts necessary to show the relation of this screen withthe rear end wall of the mill.

Like numerals refer to similar parts in the several figures.

Asshown. in Fig. 1 my improved pulverizing mill consists of an elongatedconical barrel 1 the ends of which are closed by the forward end wall 2and the rearward end wall 3. Formed on the end walls 2 and 3, concentricwith the longitudinal axi of the barrel, are the trunnions 4 and 5 whichare rotatably mounted in suitable journal bearings 6 and 7 to supportthe mill. The forward trunnion 4 is provided with a central aperturethrough which projects the feeding mechanism 8 by which material isintroduced to the interior of the mill, and the rearward trunnion 5 isprovided with a central aperture 9 through which the finished productmay escape. For convenience of manufacture the barrel 1 is formed of aplurality of sections 10, 11, 12 and 13 which are joined together bysuitable abutting flanges 14 through which extend the attachment bolts15. These sections are preferably formed of steel castings the innersurfaces of which are protected by refractory lining plates 16 in themanner well understood in the grinding art. Attached to one of theflanges 14 is a spur gear wheel 17 adapted to be connected through atrain of power transmitting mechanism with any convenient source ofpower to rotate the mill. At suitable intervals along the length of themill are positioned transverse screens 18, 19 and 20 which are concaveon the side towards the advancing material. The screens 18 and 19 dividethe interior of the mill into a plurality of pulverizing chamhers inwhich the material to be pulverized is tumbled about with a multiplicityof grinding bodies and is classified during pulverization relative tothe size of its constituent fragments, and the screen 20 is adapted topermit the escape of the finished product while retaining the grindingbodies and unpulverized material within the pulverizing chamber. Each ofthe sections 10, 11 and 12 is provided with a convenient man hole havinga removable cover 21 for the convenience of inspection and repair of theinterior parts of the mill.

As the screens 18, 19 and 20 are exposed to the erosive action of thematerial in the several pulverizing chambers, I have provided a peculiarconstruction adapted to the convenient renewal of the worn or brokenparts, and by which the supporting elements, fastenings, etc.. areprotected from the direct action of said material and grinding bodies. 7

As the construction of the screens 18 and 19 are similar, a descriptionof one will apply to both. Secured to the walls of the barrel 1 in anysuitable manner, as by the attachment bolts 22, is a spider 23, formedpreferably formed of a highly blades 43 with a marginal supportingportion 23' which rests upon the inner wall of the barrel, and havingradially extending arms 24 and a central hub portion 25, and to thisspider are attached the sectoral perforated plates 26 which constitutethe screen above referred to. hese screen plates 26 are refractory alloyof iron, and they are secured to the arms 24 of the spider by attachmentbolts 2'? the heads of which are countersunk into thematerial'of thescreen plates 26 in such manner as to expose the. least possible surfaceof the bolt head to the erosive action of the material as it slides overthe surface of the screen. At their inner ends the plates 26 are cut offto form the beveled edges 28 which are engaged by a conical wedge member29 adapted to hold the screen sections securely in place. The wedge 29is secured to the hub portion 25 of the spider by a suitable draw bolt30 the head of which is suitably countersunk into the material of thewedge. The rearward surfaces of the spider are protected by the shieldmembers 31, and 33, composed of refractory material similar to that ofthe linings of the mill, and secured in position by the bolts 30, 34 and35. The shield member 31 is provided with outwardly projecting flanges3), 37 and 38 which screen the nuts upon the attachment bolts from thedirect action of the material, and recesses are formed in the shieldmembers 32 and 33 which similarly protect the nut upon the bolts 30 and35.

The final screen 20 at the end of the pulverizing chamber is formed ofsectoral plates 39 at the outer ends of which are formed the bosses 40through which extend the attachment bolts 41 to secure said screensegments to the wall of the final sectionrl3 of the barrel. Attached tothe end wall 3 of the mill, concentric with and extending into thedischarge aperture 9, is a conical deflecting member 42the purpose ofwhich will presently appear. Formed on the rearward surface of thedeflecting member 42 are rearwardly extending blades 43 which contactwith the inner surface of the end wall 3, and through apertures in theseblades extend the attachment bolts 44, the heads of which arecountersunk in the material of the screen segments'39. These attachmentbolts securely hold the segments 39 and the'deflecting member 42 inoperative relation with the end wall 3 of the mill. The inner ends'ofthe screensegments 39 are out off to form beveled edges 45 which areengaged by a conical wedge member 46 sccuredto the deflecting member 42by the draw bolt 47. Formed on the rearward surface of the screen plates39 are radially extending blades 48 in alignment with the of thedeflecting member 42, and

fleeting member 42 into the combination zontal barrel adapted toproximity with the end wall 3 of the mill.

By these radial blades the space between the final screen 13 and the endwall 3 is dividedinto sectoral compartments adapted to rec-ive the fullypulverized material as it flows through the apertures of the screen fromthe pulverizing chamber. As the barrel revolves the material in each ofthese sectoral compartments is carried upwardly by the radial blades4348 and slides down wardly and rearwardly over the rearward surfaces ofthe screen plates 39 and dethe discharge aper- YY ture 9. ihe innersurface of the discharge aperture 9 is formed conical and expandsoutwardly to cause the material discharged from said sectoralcompartments to travel outwardly and be dischar ed at the rearward endof the trunnion 5.

In operation each of the pulverizing chambers is provided with aquantity of grinding'bodies, preferably composed of a highly refractoryalloy of iron, the size and number of which bears a definite relation tothe size of the fragments constitutin the material which is being groundin the respective chambers. Relatively coarse material is fed into thefirst chamber by the feeding mechanism 8, and as the size of itsconstituent fragments is reduced it travels longitudinally of the millthrough the successivcscreens and finally discharged at the rearward endof the mill in the manner above described.

What I claim is:

1. In a machine of the class described, the combination with a zontalbarrel adapted to revolveaboutits longitudinal axis, of a transversepartition dividing the interior of the barrel into pulverizingcompartments, said partition comprising radially ext-ending armsattached to said barrel and sectoral perforated plates secured to saidradial arms, and means toprotect said arms from the erosive action ofmaterial and grinding bodies within the compartments as the barrelrevolves.

2. In a machine ofthe class described, the combination with asubstantially horizontal barrel adapted to revolve about itslongitudinal axis, of a-transverse partition dividingthe interiorof-thebarrel into pulverizing compartments, said partition comprising aspider having a centralhub-por tion and radially extending arms attachedto said barreland sectoral perforated plates secured to said spider, andmeans to protect said spider from the erosive action of material andgrinding bodies within the compartments as the barrel revolves.

3. In a machine of the class described,

with a. substantially horirevolve about its longitudinal axis, of atransverse partition substantially -horidividing the interior of thebarrel into pulverizing compartments, said partition comprising a screensupport, a screen, means to attach said screen to said support, andmeans to protect said support and said attachment means from the erosiveaction of material and grinding bodies within the compartments as thebarrel revolves.

4. In a device of the class described, the combination with asubstantially hori- Zontal barrel adapted to revolve about itslongitudinal axis, of a transverse screening partition dividing theinterior of the barrel and comprising plurality of sectoral plates andmeans to secure said plates in fixed rela tion in said barrel, saidmeans comprising a spider-like supporting member having a rim portionresting upon the inner wall of the barrel and a hub connected to saidrim by radial arms, and means for securing the plates to said arms.

In a device of the class described, the combination with a substantiallyhorizontal barrel adapted to revolve about its 1ongitudinal axis, of atransverse screening partition dividing the interior of the barrel andcomprising a plurality of sectoral plates and means to secure saidplates in fixed relation in said barrel, said means comprising aspider-like supporting member having a rim portion resting upon theinner wall of the barrel and a hub connected to said rim by radial arms,means on the barrel engaging said rim to hold the member in fixedposition, and means for securing the plates to said arms.

6. In a device of the class described, the combination with asubstantially horizontal barrel adapted to revolve about itslongitudinal axis, of a transverse screening partition dividing theinterior of the barrel and comprising a plurality of sectoral plates andmeans to secure said plates in fixed relation in said barrel, said meanscomprising a spider-like supporting member having a rim portion restingupon the inner wall of the barrel and a hub connected to said rim byradial arms, means for securing the plates to said arms, said securingmeans passing through the arms, and means on the arms for shielding thesame and said secur-- ing means from the erosive action of the materialwithin the barrel.

7. In a device of the class described, the combination with a barreladapted to revolve about its longitudinal axis, of a transversepartition dividin th interior of the barrel and comprising a pluralityof sectoral perforated plates, a spider-like member for supporting saidplates fixed position and rigidly secured within the barrel, said memberhaving radially extending arms, means passing through the arms andserving to secure the plates thereto, and devices upon the rear surfacesof said arms for protecting the same against the erosive action of thematerial within the barrel.

8. In a device of the class described, the combination with a barreladapted to revolve about its longitudinal axis, of a transverse concavepartition dividing the interior of the barrel and comprising a pluralityof sectoral perforated plates, a spider-like member for supporting saidplates in fixed position and rigidly secured within the barrel, saidmember having radially extending arms, means passing through the armsand serving to secure the plates thereto, and devices upon the rearsurfaces of said arms for protecting the same against the erosive actionof the material within the barrel, said devices being provided withsockets for receiving and shielding the said securing means.

In testimony whereof, I affix my signature.

ALEXANDER M. READ.

